Improved Noise Reduction for Audacity

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mrbumpy409
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Improved Noise Reduction for Audacity

Post by mrbumpy409 »

About a year ago, I was working on a sampling project and found myself a bit disappointed with Audacity's built-in noise removal feature. After a bit of research, I discovered a patch by Marco Diego Aurélio Mesquita that adds spectral subtraction as an option to Audacity's noise removal dialog. I found this gave me better results. I then discovered a noise coring patch by Jérôme M. Berger (described here) that also does wonders for some audio.

If you don't mind compiling from source, it's pretty easy to add these improved noise reduction options to Audacity. Here's how:
  1. Uninstall Audacity if you already have it installed.
  2. Download the Audacity source code. The latest version as of today is 2.0.2.
  3. Extract the source code tarball.
  4. Make sure you have the necessary dependencies to compile Audacity (see section 4 in the README.txt included with the Audacity source code).
  5. Download the spectral subtraction patch attached to this post:
    audNR.patch.tar.gz
    patch for spectral subtraction noise removal
    (2.83 KiB) Downloaded 61 times
    ...and extract it into the audacity-src-2.0.2 folder that was created when you extracted the Audacity source code.
  6. Download the noise coring patch from here (click the download link on the right-hand side of the page). You will need to extract noise-coring.patch from the downloaded zip file and place it in the same folder you placed the other patch.
  7. Patch the source code by running the following commands from within the audacity-src-2.0.2 folder:

    Code: Select all

    patch -p 1 < audNR.patch
    patch -p 1 < noise-coring.patch
  8. Assuming you didn't get any errors during the patching process, you are now ready to compile. Run the following commands in order, noting that each one must succeed without errors before you can proceed to the next one:

    Code: Select all

    ./configure
    make
    sudo make install
    If you get any errors after running ./configure, you may be missing dependencies. Install the missing dependencies and then try running ./configure again. Hopefully, you won't get any errors during make.
  9. If all three commands completed successfully, then Audacity should be installed, complete with new noise removal options. Start up Audacity and go to the Effects menu. You should now have two noise removal options: Noise Coring and Noise Removal. The Noise Removal effect will have new sliders for Subtraction and Power.
Please note: the attached patch is only tested with Audacity 2.0.2; your mileage with other Audacity versions may vary. The patch also changes the noise removal effect's FFT size from 2048 to 8192, which can cause the noise removal effect to take longer to process, but the audio results are much better.
danboid
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Re: Improved Noise Reduction for Audacity

Post by danboid »

Thanks v.much ("She's real fine my" mrbumpy)409 - that sounds very useful indeed!

In case you miss my reference, there was a song about 409's on the Beach Boys Little Deuce Coupe album - prob my fave after Pet Sounds + Today!
xiha11
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Joined: Wed Nov 21, 2012 10:59 pm

Re: Improved Noise Reduction for Audacity

Post by xiha11 »

Thanks from me too for your accurate guidelines, mrbumpy409! Spectral subtraction noise reduction had been on my want list for years.

Successfully installed on Mint 9 after installing 2 dependencies. :D
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